So, here is the solution that worked for me: For facebook options, I already had "user_photos" and "friend_photos" as part of the scope. "friend_photos" is not really relevant here. I had to ADD "user_checkins" to the scope collection to get all of the photos that I had in my given album. So here it is that I am using now, and getting things working for me. Graph API Explorer was super helpful for me when I was investigatiing this.
var facebookOptions = new Microsoft.Owin.Security.Facebook.FacebookAuthenticationOptions{...};
facebookOptions.Scope.Add("email");
facebookOptions.Scope.Add("user_about_me");
facebookOptions.Scope.Add("user_events");
facebookOptions.Scope.Add("user_groups");
facebookOptions.Scope.Add("user_likes");
facebookOptions.Scope.Add("user_photos");
facebookOptions.Scope.Add("user_videos");
facebookOptions.Scope.Add("user_checkins");
facebookOptions.Scope.Add("user_friends");
facebookOptions.Scope.Add("user_location");
facebookOptions.Scope.Add("user_photo_video_tags");
facebookOptions.Scope.Add("user_actions.music");
facebookOptions.Scope.Add("user_activities");
app.UseFacebookAuthentication(facebookOptions);